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  <title>Document</title>
</head>
<body>
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            { 'id': '29', 'pid': '',    'name': '总裁办' },
            { 'id': '2c', 'pid': '',    'name': '财务部' },
            { 'id': '2d', 'pid': '2c', 'name': '财务核算部'},
            { 'id': '2f', 'pid': '2c', 'name': '薪资管理部'},
            { 'id': 'd2', 'pid': '',     'name': '技术部'},
            { 'id': 'd3', 'pid': 'd2', 'name': 'Java研发部'},
            { 'id': '2g', 'pid': 'd2', 'name': 'Python研发部'},
          ] 

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            console.log(item,'item');
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              item.children=[]
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            const parent=mapObj[item.pid]
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              parent.children.push(item)
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          })

          console.log(new_arr,'new_arr');
  </script>
</body>
</html>